By Rick Hazlett
millennium is an interesting span of time--so long that it is an abstraction to most people yet so short that it is of trivial interest to geologists. But a millennium encompasses profound historical changes.
Compare the 11th century, when a vestige of the Roman Empire was a world power, with the verge of the 21st, when Byzantine Rome is a shade of history. Important geological change, we now know, can also occur in a thousand years. A millennium is a bridge between human time and Earth time.
The coming and going of millennia are also grand occasions of anxiety for those with apocalyptic visions. Our own view of the coming millennium is rich with forecasts of doom, but with a more respectable twist for the student of reason. I am not referring to the Y2K bug, but to a broad environmental perspective that holds that human beings, like a cancer, have become so successful that they are destroying the world that gave them birth. The Earth, in short, is suffering in the late 20th century from acute "anthropathology."
Each year the human race consumes about 0.6 percent of all new plant growth on the Earth. That statistic may sound modest, but it becomes more impressive when you consider the amount of new plant growth we use or destroy in building our homes, making paper and other products, and eating other animals. In all, human activity accounts for a whopping 40 percent of all the energy fixed by photosynthesis worldwide.
If population forecasts that project a doubling of human numbers by the middle of the next century come true, our use of available photosynthetic energy might climb to 80 percent. We're unlikely actually to attain that exalted level of consumption, but no doubt we shall try. No wonder some scientists are concerned about the collapse of global ecosystems and our continuing ability to feed the human race. From an ecological perspective alone, our astonishing economic growth, exploitation, material amusements and resource consumption can't last much longer.
Consider this consumption limit in another way. Even given current population levels, the planet cannot produce the food it takes for everyone to eat like an average citizen in the United States. Each of us in the U.S. requires a mean of 0.6 hectares of land--an area about 200 feet square--to produce the food we need, both in grain and meat. (Much less would be required were we to shift to vegetarian diets, an unlikely scenario.) Worldwide, there are about 1.5 billion hectares of arable land. With the global population at 6 billion, this averages out to only 0.25 hectares per person, less than half the American requirement.
Passengers on the Global Titanic
Thus, we live in a world of consumerism increasingly in collision with its limits. A colleague of mine likens people living in developed countries to passengers on the Titanic, trapped by dependency on a lifestyle that will, in the end, prove disastrous. We enjoy the comforts wealth has brought us on our voyage without being concerned about where or how our ship is being navigated. A short-sighted media; narrowly focused education; parochial political agendas; the endless demands of "getting ahead"; and other biases safely keep most of us unaware or--worse--distracted to the point of not caring.
So here is my forecast for the fate of the American Dream--and it is a no-brainer. The new millennium, even the next century, will dislocate capitalist economics, religion, urban life, human self-image, even liberal arts education in ways we can only dimly imagine but which will certainly be drastic.
A good example is the imminent exhaustion of the world's inexpensive petroleum. Never again, perhaps, will so many people be able to move so easily, so cheaply or so swiftly. We may truly live in the Golden Age of mobility. And its end may be in sight.
Alternatives to gasoline-powered internal combustion engines exist, to be sure. Natural gas is likely to be our next major source of power for transportation. But no known alternative provides both the cheap power and range of contemporary petroleum-based transport. Personal transportation based on any known alternative will, in general, provide shorter, slower, more costly drives. The jetliner, which has made the world so small, may go the way of the passenger pigeon, and the world may grow large again. It also may grow more urban as the suburban lifestyle of places like Los Angeles grows too expensive to maintain.
And that's not even counting the effect of the end of cheap oil on the production of food, which is highly dependent on synthetic fertilizers made from petroleum products, or the skyrocketing price of transporting and refrigerating that food on its way to market.
Not the end of the world, perhaps, but it might well qualify as the end of the world as we know it.
And when do most resource economists expect cheap oil to run out? Believe it or not, the answer is not centuries away. The projected date is 2025. I am an optimist in these matters and expect another few decades based on improved recovery techniques. But most geologists no longer believe substantial new oil reserves can be found. This is why international estimates for the depletion of cheap supplies have remained constant since around 1980.
Of False Alarms and Time Bombs
But that is only one of a range of environmental concerns that will cast their shadow on our celebration of the new millennium. To get a better handle on them, I sort them into several useful categories.
The first I call the False Alarm category. These are environmental concerns that turn out to be less serious than anticipated, but are maintained at great cost by political agendas, lack of scientific data and media hype. A good example is concern over asbestos, which comes in several mineral forms, by far the most common of which is quite benign due to the shape of its fibers. Countless buildings and untold millions of dollars have been wasted in the pointless removal of this valuable fire-retardant, which is easily identifiable under the polarizing microscope. Fortunately we have gotten rid of some of the bad stuff as well.
Then, there is the Head in The Sand category. Many people know we have a problem--like the depletion of oil, the overharvesting of timber or the destruction of fisheries--but we party on in our sport utility vehicles, deliberately ignoring what will amount to someone else's future distress. It is certainly good for our short-term economy. In fact, probably half the population, including half of Congress, doesn't even believe there is reason to be disturbed.
Then, there is another, more serious category of concern--The Ignored Time Bomb. This is a definite problem about which most people remain happily ignorant. The Ogallala Aquifer falls in this category.
Eighty million years ago, the Rocky Mountains began to rise. As the land to the east emerged from the sea, rivers and streams began to cut into it. By around 20,000,000 years ago, sediment from the mountains, coupled with climate change, filled many of these river valleys. The infillings became the Ogallala Sandstone, a geological formation hundreds of feet thick that can store vast amounts of groundwater. We dig wells into this aquifer--pull out its water to irrigate an important part of America's grain crop--14,000,000 acres, in fact. That's 40 percent of all our wheat, flour and cotton. Crop yields are three times what they are on adjacent, unirrigated farmlands. A considerable amount of our balance of trade depends upon this aquifer--25 percent of all U.S. feed-grain exports are grown with this water.
But where did all that water come from? Geologists believe most of the Ogallala water was produced at the end of the last Ice Age as glaciers in the Rockies melted back. The Ogallala water is mostly 15,000 years old, or older. It would take at least that long for the aquifer to be replenished at today's rates of rainfall if it were completely drained.
And we're doing an excellent job of draining it--fast. We pull out the equivalent of the entire flow of the Colorado River from the aquifer every year. The level of the underground water in the aquifer is dropping at a rate of about 10 feet a year at present. This means that by 2045 or thereabouts the whole system will be sucked dry as a bone.
When that happens, domestic food prices will increase substantially, and a mainstay of international trade will also disappear--unless we can import water from elsewhere. But who will give up their water for the American Midwest? Do we take it out of Lake Huron or Lake Michigan? Do we annex Saskatchewan from Canada and divert water from its marshlands by gravity flow? Anyway you cut it, even if we preserve High Plains productivity, the real cost of food in the U.S. is likely to climb because of the expense of constructing alternatives to the waters of the Ogallala.
Even more than the depletion of cheap energy reserves, the overtapping and toxic pollution of fresh groundwater supplies is a grave resource issue. We can live without the oil if need be, but not without fresh, clean water and the food that it grows.
The Jury Is Still Out
Finally, there is the Jury Is Still Out category. This category, unfortunately, includes some of what might be the most severe environmental problems, such as greenhouse warming and the Global Conveyor.
The Global Conveyor is a a vast current that links all the world's oceans, mightier than the flow of all the world's rivers combined. Seawater varies in density according to its temperature and salt content. In the Atlantic, a narrow ocean, seawater evaporates faster than it does in the Pacific. This makes the Atlantic water saltier and denser. In the North Atlantic, which is very cold thanks to the Greenland ice sheet, this salty water gets even denser and settles to the bottom in a huge mid-ocean waterfall.
As the water drops three miles to the seabed, replacement water rushes in behind it. As in a chain reaction, that water in turn needs replacing, and the Conveyor begins. The cold water flows down the spine of the Atlantic, round the tip of Africa into the Indian Ocean, then around southern Australia and into the Pacific, where it rises to the surface in the northern Pacific and begins its journey back around the world. It is truly a gigantic liquid circulation cell.
The oceans moderate the climate of adjacent lands. This is important, since over half the human race lives within a hundred miles of the sea. Northwestern Europe, at the same latitude as the Alaska Panhandle and central Canada, has moderate winters and long, wet summers thanks to the Global Conveyor, which draws warm equatorial waters up against the European coast. If it weren't for this, England would be as frigid as Labrador.
There is now compelling evidence--from seafloor sediments, the geochemistry of ice cores and fossils--that the Earth's climate is capable of sudden, dramatic changes, decadal in scale, strong enough to throw global agriculture for a loop in temperate climates, where in fact most agriculture is located.
The last such catastrophic climate swing occurred about 8,000 years ago, according to geophysicist Wally Broeker of Columbia University. Melting of the Ice Age glaciers that covered Canada released vast amounts of fresh, low-density seawater across the North Atlantic, shutting down the Conveyor and forcing it into another mode of circulation much different from the present. As a result, Northwestern Europe went into a prolonged deep freeze.
Since today's buildup of coal and petroleum-based greenhouse gases matches that of the natural buildup at the end of the last Ice Age, Broeker points out that the Greenland ice sheet may be vulnerable to sudden melt-back. Human activity, he warns, "might trigger yet another ocean reorganization and thereby [cause] associated large atmospheric change. ... Should this occur when 11 to 16 billion people occupy our planet, it could lead to widespread starvation."
With keen interest, oceanographers are striving to evaluate this spooky hypothesis.
The jury is still out.
For Future Generations
Paradoxically, in a world glutted with information, it has become harder than ever for most of us to piece that information together meaningfully--so hard, in fact, that we may feel overwhelmed, even immobilized, before such complex, yet critical, issues. In the media, many potentially devastating environmental problems, lacking any immediate human-interest angle, go altogether ignored. Available information on other issues is speculative and frequently conflicting. For this reason it is difficult to build an accurate perspective on what is happening. We must pick through a wide range of sources of varying reliability and weigh them critically, something few of us have the time to do.
But it is important to make the effort.
"The state of civilization of a people," said John C. Merriam, a noted California biologist, "may be measured by its care and forethought for the welfare of generations to come."
With that thought in mind, here are some bits of modest advice for the new millennium.
First, you need not panic at every signal of impending environmental destruction, but neither is it wise to dismiss such signals summarily, simply because not enough is known, or because it is in the interest of your business or political faction to do so.
Second, be aware that you probably don't see enough of the picture to understand what is going on--that you have to work and read hard and wide to get a handle on what is happening.
Finally, don't be scared of science. Without knowing some basic science, we are sorely handicapped in evaluating new environmental issues. We only have a partial basis to think critically. It's like trying to navigate without a rudder.
And don't fret Y2K. It's really just peanuts.
Richard W. Hazlett is associate professor of geology at Pomona College.
--Illustration by Dugald Stermer
